On Fri, Jan 05, 2018 at 02:13:22PM +0000, Chris Wilson wrote: > When reprioritising a request, we build a list of its dependencies in > topological order. This should leave our origin request as the first > element in our list, if it moves we have a dependency cycle and severe > breakage. Assert that it doesn't move. > > Complete, but expensive checking is done by swfence, this assert is more > about documenting the topologically ordered list. > > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> > Cc: Michał Winiarski <michal.winiarski@xxxxxxxxx> Reviewed-by: Michał Winiarski <michal.winiarski@xxxxxxxxx> -Michał > --- > drivers/gpu/drm/i915/intel_lrc.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c > index 4e150b095a11..42705e3875cd 100644 > --- a/drivers/gpu/drm/i915/intel_lrc.c > +++ b/drivers/gpu/drm/i915/intel_lrc.c > @@ -1050,6 +1050,13 @@ static void execlists_schedule(struct drm_i915_gem_request *request, int prio) > } > } > > + /* > + * We should never have a dep cycle back to ourselves, leaving > + * the original request as the origin of our topologically sorted > + * list. > + */ > + GEM_BUG_ON(list_first_entry(&dfs, typeof(stack), dfs_link) != &stack); > + > /* > * If we didn't need to bump any existing priorities, and we haven't > * yet submitted this request (i.e. there is no potential race with > -- > 2.15.1 > _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
